A collaboration between Zenith and USM Haller, the Zenith Defy Chronograph USM offers a new definition of an ‘architect’s watch’
When imagining the perfect watch for an architect, certain images immediately come to mind. As you might expect, elements like openworked dials, bold geometrical cases and stripped-down designs rank high among the list. It’s fair to say then that the new Zenith Defy Chronograph USM, created in collaboration with Swiss modular-furniture pioneer USM Haller and recently unveiled at Geneva Watch Days 2025, doesn’t appear to fit this criteria at first glance.

Adorned with vibrant blue, yellow, green, or orange dials, the timepiece offers a playful and energetic allure that belies its structural elegance. Take a closer look, however, and you’ll find that its 37mm octagonal steel case and fourteen-sided bezel—elements taken straight from the very first Defy watch from 1969—give it a startling sense of industrial clarity.
In many ways, Zenith’s decision to pull from its archives makes perfect sense. A collaboration between two Swiss houses defined by innovation and heritage demands a design that honours their histories and reflects their shared principles. After all, both Zenith and USM Haller broke boundaries in the same era of mid-century Swiss ingenuity, with architect Fritz Haller patenting his modular furniture system in 1965, and Zenith unveiling the groundbreaking El Primero chronograph just four years later in 1969.

It’s apt then that the Zenith Defy Chronograph USM is powered by the El Primero 400, the calibre that has defined the Manufacture in contemporary watchmaking. Beyond its bold case geometry and historical richness, however, the timepiece further integrates a series of thoughtful elements that accentuate its architectural allure. The applied square hour markers, for example, are etched with horizontal grooves, providing the timepiece with an industrial texture. More than that, the chronograph’s central seconds hand is tipped with a luminous sphere, a direct reference to the polished ball joint at the core of the USM Haller system.



Elsewhere, three overlapping silver subdials, decorated with concentric guilloché, balance the case’s angularity with softened, circular forms. The bracelet, meanwhile, reprises the open “ladder” design first produced by Gay Frères in 1969, lending the watch a lighter, more architectural profile on the wrist. Together, these elements ensure the timepiece, through every surface, index, and line, speaks to the principles of modularity and proportion.
Limited to just 60 pieces per variation, the Defy Chronograph USM, with its 55-hour power reserve, is presented in a custom USM Haller timepiece chest—an inspired finishing touch to an already architecturally intriguing watch.